Hotel Rate Policy - Average night rate for calculation

Requirement - As expense Auditor I want the system to validate hotel expenses based on the average nightly rate, So that travelers are not flagged for a single expensive night if their overall trip average remains within policy limits.

Example - Night 1 room rate 100, Night 2 Room rate 700, Night 3 Room Rate 400

Policy - 400/per night

Desired Logic: The system should calculate the Average Rate ($400) and use this figure to determine if the expense is within policy, rather than flagging Night 2 specifically.

Why? Usually hotel can have expensive weekend night and cheap weekday night rate, if this is still within policy then employee is policy complied. Additionaly, some portal shows average rate at the time of booking and employee has no idea about specific nightly rate.